Tree stand



FIG. 1 is a perspective view of the tree stand showing the new design;

FIG. 2 is a frontal elevation view, views 60 degrees to the right rear thereof and 60 degrees to the left rear thereof being identical thereto;

FIG. 3 is a top plan view view; and,

FIG. 4 is a bottom plan view. 

The ornamental design for a tree stand, as shown and described. 